1. Field of the Invention
This invention relates to a process cartridge and an electrophotographic image forming apparatus.
The electrophotographic image forming apparatus is an apparatus for forming an image on a recording medium by the use of an electrophotographic image forming system. Examples of an electrophotographic image forming apparatus include, for example, an electrophotographic copying apparatus, an electrophotographic printer (such as a laser beam printer or an LED printer), a facsimile apparatus and a word processor. Also, the process cartridge comprises at least one of charging means, developing means and cleaning means and an electrophotographic photosensitive member integrally made into a cartridge, which is removably mountable onto a main body of an electrophotographic image forming apparatus.
2. Related Background Art
An electrophotographic image forming apparatus such as an electrophotographic copying apparatus or a laser beam printer has, for example, a photosensitive drum, and carries out known processes such as charging, exposure and development in succession on this photosensitive drum to thereby form a toner image on the photosensitive drum, and transfers the image onto a recording medium, such as transfer sheet. Thereafter, the step of removing any toner remaining on the photosensitive drum by a cleaning device is executed to form an image.
In recent years, such an electrophotographic image forming apparatus has come to adopt a process cartridge system to achieve compactness and ease of maintenance thereof. This process cartridge system comprises a photosensitive drum and process means acting thereon such as charging means, developing means and cleaning means integrally made into a cartridge, which is removably mountable onto the main body by a user himself.
When the process cartridge is to be mounted or dismounted with respect to the main body, a guide portion provided on a side of the process cartridge may be guided along a guide groove formed in the main body to mount of the process cartridge smoothly.
However, the user may try to mount the process cartridge laterally in reverse or longitudinally in reverse with respect to the main body. Accordingly, means for preventing such incorrect mounting becomes necessary.